


Surprise

by sunshineglow118



Category: Invader Zim
Genre: College Student Dib, College Student Zim, M/M, Mating Cycles/In Heat, Omega Dib, Omega Verse, Tentacle Sex
Language: English
Status: Completed
Published: 2019-12-12
Updated: 2019-12-12
Packaged: 2021-02-25 21:54:24
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,191
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21772525
Author URL: https://archiveofourown.org/users/sunshineglow118/pseuds/sunshineglow118
Summary: ABO verseDib gets a surprise heat and Zim helps him through itPure smut
Relationships: Dib/Zim (Invader Zim)
Comments: 21
Kudos: 216





	Surprise

**Author's Note:**

> Mark this down for weird things I've now written and put on the internet. I've been reading and haven't seen many ABO's- naturally I had to change that.  
> Strange times. Please enjoy this monstrosity.

Zim had noticed some changes in his human over the past couple of days. Dib suffered from a couple of inferior human ailments- insomnia, the one that kept him awake in the evening. Dib had medicine for it- but he complained that the chemical components in the drug would make him so tired he didn’t want to get up at any point of the day.

They were in college, the next level of human learnings from hi-skool. To appease his parental unit, Dib had chosen to study quantum physics- taking courses that would help him prove the existence of the paranormal to other humans within the field of science.

Zim, in their final year of hi-skool, had finally relented to the truth that he was on earth as a means of exile and isolation. The knowledge burned him, leaving him a husk of an irken. For days, he neglected his feedings, bathings, and other routines- laying in a puddle of his own misery; content to fade from existence.

Gir and minimoose, seeing their master and creator, made for a memorable journey to Dib’s house, blowing a hole in the side of Dib’s room. Dib found the two robots jumping on his bed, minimoose hovering, when he arrived back from hi-skool. He didn’t get an answer from either creature as to who ate his plans on finding the Lock Nessie Monster.

Upon his arrival to the base, large beams beginning to fall between the houses Zim was poaching energy from, the gnomes parted way, allowing him entrance. The robots dragged him into the house and down to the lower levels- presenting him to their broken master with a demand that he fix Zim.

Dib hesitated, naturally- they had their fights, brutal and bloody in the past. But like a river, their more recent battles were calm, almost playful in the way they sought out each other’s weaknesses. Teeth were still bared- but lips were turned upward in the hint of a smile. Several times, they had teamed up, their past battles making them a solid and unstoppable unit against a common enemy.

Gir shared his waffle syrup with Zim, handing Dib the bottle to feed the irken. Zim near delirious with weakness, only put up a fight in the beginning, his frail arms shaking as he tried to push Dib away. The pak legs creaked from his back, but their jabs were uncoordinated and ended up exposing Zim more than protecting him.

It had taken several months of coaxing and fighting to get Zim back to the way he was- rather, improved. The irken spent the first few months wallowing in his sorrows. Dib listened to the irken for a while, but inevitable snapped when Zim regressed in his progress when the Tallest called. Dib stood out of the camera’s angle, his heart hammering in his chest as Zim promised he would do anything for their favor. They had invited him back to the Massive, a celebration in mind.

“Zim,” Dib said, his back to the irken, “I know you- I know you won’t stop or be stopped by anything.”

Dib left before Zim could say anything else, leaving his eye water on the floor.

Zim broke Earth’s atmosphere, looking at the blue and green planet with its dying weather patterns and inferior race. He spent a couple of minutes just observing the planet, watching the wind patterns slowly move from west to east. Gir was eating the last of his waffles, a recipe welded into his arm so he could have them wherever he went- minimoose making quiet whining sounds as they hovered above the ozone layer.

The computer only asked him once if he would like to take off, leaving the marble behind for his home race. He turned the ship, making way for his journey as it would take a human year to make it to the new location the Massive lurked.

But he looked back and just stared at the planet.

Zim landed back on earth with little fanfare. Part of him wanted to run to his enemy, proclaiming his permeate stay on the planet but he didn’t desire to feel… _desperate._

Dib was elated, showing his excitement by swooping up the smaller alien into his arms and holding him close enough Zim could hear the rushing of blood through his heart- a hollow sound with rapid beats. The human’s hormones were happy and Zim could smell how his own pheromones responded.

Zim did not contact the Tallest.

The Tallest did not contact Zim.

The end of their hi-skool was the beginning of their change in relationship. Now that Zim was committed to the planet- his first method of repairing the atmosphere was changing the water so he could survive it. Dib had an umbrella, an amazing invention- even he could admit, in his hand, at the ready. Zim was nervous- rain falling to the ground, he stepped out from the safety of his base without protection.

Rain, as he learned, felt like little needles when it was clean. Dib joined him in the rain, splashing in puddles with Gir and minimoose quickly joining in. Zim even allowed himself to get muddy, tracking prints into the house when Dib’s skin began to ‘prune.’

He remembered the rain fondly now, perhaps a bit biased since Dib had pulled him close and connected their mouths.

Sex was a newfound discovery as well.

There were fights, verbal, rarely physical unless they were sparing now. The most memorable one was when Zim, after falling back on his emotions, lashed out at Dib, exclaiming that he only saved the irken because of his secondary gender.

A touchy subject for Dib. The third year of hi-skool, Dib learned of his origins: clone. He was defective in his own way, all the equipment of an omega but none of the hormones. Humans avoided him- Dib had no scent other than the one already associated with whatever foods or perfumes he encountered. Humans of all genders interacted with him, but not enough to form solid connections. Gaz, being the second clone, was an alpha through and through. She had the scents and equipment while Dib, the prototype as listed on his encrypted file, had none.

The irken, after saying such words, thought Dib would lash out, fight back, but the human deflated. The fight left him and he walked out of the base- going back to his house and remained their for several days until Zim groveled enough to be allowed entrance into the house. Between insulting his mate and his entrance into the house, Zim had researched everything he could on how to make it up to his human.

Zim approached the topic of omega with as much caution as he would a frozen lake, each step and word calculated in a fashion that was challenging to him. Dib gradually opened up, trying to explain to Zim why it was hard to be an omega but not an _omega._

Defective.

College brought new freedoms to both of them- a place they could study more advanced topics. Zim somehow got his hands on one of the abandoned buildings near the campus, rumors of it being haunted scored him several brownie points with his human. The building was renovated overnight, gnomes protecting the front garden and sprouting from the side of the brick walls. Several students laughed at them, but rarely did they come too close.

Unless they were delivering foods and food like products.

Zim was studying Environment, his days filled with classes and nights with Dib and the rest of his family. When Dib would sleep, Zim would use the hours to get work done, sending drones to the polar caps or the ozone layer.

Odd things happened over the last days.

Dib, who commonly made the bed once he moved in with Zim, changed the sheets so they were coiled in the center. He claimed the nest with a smile, shuffling his body into the lowest point with Gir and Minimoose held ‘hostage’ in his arm.

The irken had a far superior sense of smell than the human, he noticed the change in Dib’s scent, but it was subtle- slightly sweeter than normal. When he tried to coax the human into a round of mating by giving Gir a task that would remove him from the nest, Dib pulled his lips back in a snarl. His flat teeth were not as threatening as Zim’s, but a human bite still hurt. While Zim believed Dib would not actually bite him, the behavior was odd; Dib pulling both squealing robots deeper into the nest, rolling his flesh body over the machines to keep them in nest. Dib then ran his chin over the robots.

The next day, Dib woke with a horrible headache that only: ‘goes away when I’m resting on you.’ Zim proclaimed himself a healer and thought nothing more of the sweet scent. A sickness was not passing over his human- stress was surely the answer. Dib wore one of Zim’s shirts- looking more like a crop top than a shirt, but he skipped his classes so he didn’t care about the loss of an article of cloth.

Zim wasn’t sure why he even attended human classes. The lab was filled with algae samples- the professor drone speaking in a monotone voice through the box about the different kinds that grew on the planet. His phone buzzed on the table- a voice recording from Gir, who either didn’t understand the methods of text or didn’t care. Zim connected an ear-piece to his phone wirelessly, but held it away from his ‘ears’- Gir enjoyed screaming.

Gir’s message rambled about waffles, loud enough to earn him glares from other students. He turned the message off, making a note to ask his SIR unit to keep messages brief.

Then his phone began to blow up, metaphorically of course, it only happened once!

He growled at it, debating throwing it from the window, but it wasn’t Gir texting, but Dib.

**Come back to the apartment**

**NOW!**

**Something is wrong with me**

**Zim pls**

**I NEED you**

Zim was already out of his seat, pak packing his things away as he raced out the door. When he broke from the school’s hallways, his pak legs extended and ate the ground as he made his way off campus. ZIm climbed the side of the building- smashing through the window that lead to their kitchen.

“Master!” Gir’s eyes flashed red saluting to him, but quickly turned blue, “somethings wrong with Mary- he’s making sounds.”

The irken could smell it first, a powerful sweet smell that nearly crippled him as he got closer to the door.

“Impossible,” Zim said, his body beginning to respond. Dib had assured him he’d never been through one of the fabled ‘heats.’

No hormones

No heat

Yet, the scent was everything his research told him it would smell like: intoxicating.

He could feel himself salivating, tongue stretching out of his mouth to taste the air. Zim took his boots and gloves off, knocking once on the door to warn the human of his approach to the nest, then entered.

Dib was quite the sight- caught in the throws of self-pleasure. One of the toys was lodged in his hole, now dripping with natural lubricant rather than the fake stuff Zim made.

“Finally,” Dib said, rocking back down onto the toy. “Get over here,” he growled.

Zim was good at following orders. He stripped himself of his clothing as he approached the foot of the bed. Dib was kneeling, inclined backwards so he could grip the toy with his hand as he rode it.

“Contraceptive,” Dib growled when Zim stretched his hand out to touch- his scent turning sour, nearly suffocating him in a new way. Zim backed off the bed, hands raised slightly like he were dealing with bees.

“I need a sample of your,” he gestured to the dark stained sheets.

“You want my slick?”

Zim actually doubted Dib meant to say it in such a voice, thick with pleasure and half hooded eyes as he resumed his movements on the toy.

It was one that Zim made, not as thick as his own mating organ- but it had animatronics within it, meant to learn the patterns of pleasurable mating activities and then intensify. There were irken letters up the shaft, words Dib could now understand as different versions of: zim and mine. Zim dropped to his knees, slowly shuffling back over to the bed. Dib looked delicious riding the cock he made for his pale mate. The closer he got to the human, the thicker and sweeter the scent.

“Give me the toy, Dib,” Zim growled, forcing himself not to look at his mate’s hole, sure that his resolve would snap and he would mount the human in a matter of moments. Dib growled back at Zim, but his hips stopped riding the toy- arguably worse for the irken.

“Please hurry,” Dib whined, laying on the bed with his back arched back now he was empty. Zim didn’t leave his human’s side, taking the dildo from him. His pak leg reached out, swiping a little fluid off. They could both hear the machine changing chemical compounds that would prevent any breeding. Zim took the opportunity to lick the fake cock, eyes fluttering at the taste.

“Zim,” Dib cried out, his fingers reaching for his body. Zim rushed forward, dildo licked clean. He kissed his human, legs resting on the side of his ribs to his tongue could trace his mates mouth. Dib’s blunt fingernails pulled at his green skin, making their way up to his antenna and stroking them.

“You smell very good,” Zim slurred, moving to mark the human’s neck with his own bites. Previously, Dib had never reacted as strongly as he did now, with his sharp teeth on pale flesh pulsing blood to and from his brain and heart. “Can I eat you?”

“Yes,” Dib said, already shoving Zim lower on the bed. The chemical was still synthesizing, pak seeming to move faster with such motivation. “Maybe you need a more direct sample,” he huffed.

Zim didn’t waste time with further words, hooking Dib’s legs over his shoulder and face into his crotch.

His tongue was longer than a humans, more flexible and ribbed with small buds that were meant to gather a better idea of the air in whatever environment an irken was meant to conquer. The _alieness_ made his human scream in pleasure every time. Now, it seemed to be heightened even more. Zim could see that his human’s blood was closer to the surface of his skin, sweat permeating in the air of the bedroom. The nest the human made only had an echo of Zim’s own scent on them, since his human’s slick had made a spot on the mattress.

Divine.

Better than any snacks made by the massive.

Zim should bottle this stuff.

Dib normally cried out his name when his tongue was inside or wrapped around him. But there was a sound Dib made, when he was so beyond pleasure, his vocal box seemed unable to process a proper sound for the pleasure his brain was experiencing- a low whine. Zim did not get to hear the low whine often, and when he did, he prided himself on being a good mate. Dib’s desperation caused the low whine to pitch out of his mouth, hands digging into the sheets.

His biological nature had competed the corresponding chemicals, tongue pulling at the sweet spot males had within them. Zim remained in his human for a few mores seconds, pulling an orgasm out of his mate.

Once, they had watched porn together, an alpha and omega during a heat. Dib had explained what was happening- how the human bodies were both working. There was never any slick that dripped out of Dib, no matter how many times Zim got him to whine. An orgasm was like an alpha-fluid shooting from his cock.

Zim left pierce marks on Dib’s hips when his slick gushed out, wasting none of it on the sheets. Dib was pleading, pulling away from him now. Zim allowed it, wiping his hand over his face to remove the fluid.

Zim hooked Dib’s legs over his shoulder, the height difference a long ago solved problem. Zim’s genetalia unfolded from their sheet, pink tentacles sliding over one another as excited as he was. The protective tri-folds spread themselves wide, exposing his entire mating organ to Dib.

“Please,” Dib panted. Zim was speechless- rare, as he guided his tentacles to Dib’s wet hole. They reacted on their own, feeling around for Dib, then sliding in quickly, drawing Zim’s hips close for the two of the tri-folds to wrap around Dib’s balls while the other secured itself under Dib’s tailbone.

“Fuck,” they both said, Zim’s head resting on Dib’s stomach as his tentacles shifted inside his wet channel. The slick was unlike any of the lubricants they had tried- seeming to urge his own organ into mating faster and harder.

Zim thrust against Dib, pulling his sex organ out as much as he could with his tri-fold keeping them close together.

“More,” Dib cried, scratching Zim’s back.

“I can’t,” Zim said, locked close with the fold. His sex organ was semi-intelligent, acting on their own accord to mate. They were reacting to his own pheromones, horny enough to not let him out of Dib to thrust against him.

“Let me ride you,” Dib said, breathless as he pulled Zim close, dropping his legs to flip them over. He sat deep on Zim’s hips, the smaller alien enjoying the full weight of his human, tri-fold pulsing against his body. Dib cried out, one hand braced against Zim’s chest bone. The pack legs lifted him slightly, puncturing the wall behind the bed so Dib could better balance on Zim.

“Zim yes,” Dib shouted, riding him on the mattress, the tri-fold letting him part a bit to get deeper. The tentacles thickened as they pumped deeper into Dib, trying to keep his hips as close to Zim as possible. Dib and Zim rarely enjoyed a full connection- letting the tri-fold and tentacles do the work when they would rather thrust against themselves. Thankfully, pulling the tri-fold rarely hurt either of them.

Zim didn’t know how long Dib rode him, but when Dib came a second time, his body allowed the folds and tentacles to lock him against green hips.

“So that’s what a heat feels like,” Dib slurred, tipping to the side of the nest, Zim forced to follow his body.

“Enlightening.” Zim traced the connection of his tri-fold with Dib’s skin, hearing a flinch from him. “Zim is prepared to aid you as long as you need.”

The heat only lasted two days, both having to send messages to the skool teachers that they would be otherwise occupied the rest of the week- both mating and recovering.

Dib didn’t know what brought the heat to his endocrine system, but he was extremely glad he had Zim to help him through it.

**Author's Note:**

> Please comment- I honestly don't know what I've done here...


End file.
